Paroxysmal exercise-induced dyskinesia diagnosed using exercise test

Abstract

Background Paroxysmal movement disorders are interesting forms of hyperkinetic movement disordersthat are perplexing to the neurologist and patients. The main features are transient dystonia or choreainvolving various body parts and lasting few seconds, minutes or hours depending on the subtype. Theparoxysmal exercise-induced dyskinesia is associated with a gene mutation of (NM_145239.2:c.649dupC)in proline-rich trans-membrane protein 2 (PRRT2). This is found in an average of 45% of cases. Familialcases have 85% penetrance.Case report We report a case of a 12-year old boy with intermittent episodes of abnormal movementswhich involved his face and / or limbs. These dyskinesias occur every few days without warning.Complete neurological examination was normal. Importantly, Magnetic Resonance Imaging head andElectroencephalography were normal in association with normal haemto-biochemistry profile. The familyrecorded a video for one episode of his abnormal movement. The doctor set a challenge of 20 meters racing.He excited the patient then started the race with the attendance of the parents and the nurse. Few secondsafter the end of the race the development of the abnormal movement was judged by the parents and nursewho all agreed on the provocation test.Conclusion Paroxysmal exercise-induced dyskinesia is the commonest primary episodic movementdisorder which has its negative effect on the quality of life. The diagnosis and management are mainlyclinical. It is of paramount importance to use simple tests (exercise test) and save the patient unnecessaryworries and side effects of medications.